Author
Kazuhito Kato, Kousuke Suzuki & Chikanori Honda
Abstract
There are growing concerns about increasing carsickness in a self-driving car as drivers perform various non-driving tasks during autonomous driving. It would appear that reducing motion of the head where the vestibular and the visual systems locate effectively reduces carsickness. Hence, we developed a novel headrest with occipital bone support (OBS) that could suppress passengers’ head motion and examined its effectiveness on carsickness. In the experiment, participants sat in a minivan’s second-row seat behind a driver’s seat and watched a video on a tablet terminal during a 30-minute vehicle journey on urban roads and reported the carsickness ratings at 1-min intervals. One of four seating conditions (a combination of two seating postures, ‘upright’ and ‘relaxed’, and two types of headrests, ‘normal’ and ‘OBS’) was examined in each journey. Head and thorax motion was also acquired using wireless motion sensors. Motion Sickness Dose Value (MSDV) was calculated for each axis. The results showed that the developed OBS headrest significantly reduced MSDVs at the head, and the mean accumulated illness ratings for 30 minutes were also significantly reduced by more than 40%.